This invention relates to an injector, for example, of a rotary type, especially used in chromatography.
Japanese Patent Application Publication Laid-Open No. 2000-186985, the disclosure of which is herein incorporated by reference, discloses a micro-injector which is generally used in liquid chromatography.
As shown in FIG. 7, the above type of injector, which is a rotor 21, includes a sample chamber 22 (a flow channel) for a sample eluent to pass through and a light passage 23, both of which are provided in the rotor 21. The position of the sample chamber 22 is recognized by transmitting light through the light passage 23 and detecting the transmitted light with a light detector and, thus, the position of the sample chamber 22 is indirectly controlled.
However, since the internal diameter of the sample chamber 22 is so small, it is required to control the position of the sample chamber 22 with accuracy down to the micrometer in order to connect the sample chamber 22 to an open mouth of a capillary column at the downstream end of the sample chamber 22.
Therefore, an object of the present invention is to provide an injector that has an accurately position-controllable sample chamber.